Being a Bills fan I can't give you a Dolphins fan's input on attending a Bills away game, but I can tell you what I know.
I live a couple of hundred miles from Buffalo and try to get to one game a year. Every game I have attended, the Bills have lost.
There have been other teams fans there, Pats, Broncos, Texans, etc, (never been to a Dolphins game there), and I have never seen any problems. Even when Bills fans are in an ugly mood after those games.
People behave and enjoy themselves, as far as I can see. Like everywhere else, if your drunk and handing out abuse, or respond to fools taunting you, trouble may follow.
You don't walk across the road to where a group of grease balls are hanging out and tread on one of there toes. Mind your own business and have a good time.